<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
当前额度不够，请换个渠道发起支付<br>
倒计时<span id="time">5</span>...
</body>
<script>
    var time = 5;
    setInterval(function () {
        time--;
        document.getElementById("time").innerText = time;
        if (time <= 0) {
            location.href = "/";
        }
    }, 1000)
</script>
</html>